xref: /openbmc/linux/mm/damon/vaddr-test.h (revision 45120b15)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Data Access Monitor Unit Tests
4  *
5  * Copyright 2019 Amazon.com, Inc. or its affiliates.  All rights reserved.
6  *
7  * Author: SeongJae Park <sjpark@amazon.de>
8  */
9 
10 #ifdef CONFIG_DAMON_VADDR_KUNIT_TEST
11 
12 #ifndef _DAMON_VADDR_TEST_H
13 #define _DAMON_VADDR_TEST_H
14 
15 #include <kunit/test.h>
16 
__link_vmas(struct maple_tree * mt,struct vm_area_struct * vmas,ssize_t nr_vmas)17 static int __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
18 			ssize_t nr_vmas)
19 {
20 	int i, ret = -ENOMEM;
21 	MA_STATE(mas, mt, 0, 0);
22 
23 	if (!nr_vmas)
24 		return 0;
25 
26 	mas_lock(&mas);
27 	for (i = 0; i < nr_vmas; i++) {
28 		mas_set_range(&mas, vmas[i].vm_start, vmas[i].vm_end - 1);
29 		if (mas_store_gfp(&mas, &vmas[i], GFP_KERNEL))
30 			goto failed;
31 	}
32 
33 	ret = 0;
34 failed:
35 	mas_unlock(&mas);
36 	return ret;
37 }
38 
39 /*
40  * Test __damon_va_three_regions() function
41  *
42  * In case of virtual memory address spaces monitoring, DAMON converts the
43  * complex and dynamic memory mappings of each target task to three
44  * discontiguous regions which cover every mapped areas.  However, the three
45  * regions should not include the two biggest unmapped areas in the original
46  * mapping, because the two biggest areas are normally the areas between 1)
47  * heap and the mmap()-ed regions, and 2) the mmap()-ed regions and stack.
48  * Because these two unmapped areas are very huge but obviously never accessed,
49  * covering the region is just a waste.
50  *
51  * '__damon_va_three_regions() receives an address space of a process.  It
52  * first identifies the start of mappings, end of mappings, and the two biggest
53  * unmapped areas.  After that, based on the information, it constructs the
54  * three regions and returns.  For more detail, refer to the comment of
55  * 'damon_init_regions_of()' function definition in 'mm/damon.c' file.
56  *
57  * For example, suppose virtual address ranges of 10-20, 20-25, 200-210,
58  * 210-220, 300-305, and 307-330 (Other comments represent this mappings in
59  * more short form: 10-20-25, 200-210-220, 300-305, 307-330) of a process are
60  * mapped.  To cover every mappings, the three regions should start with 10,
61  * and end with 305.  The process also has three unmapped areas, 25-200,
62  * 220-300, and 305-307.  Among those, 25-200 and 220-300 are the biggest two
63  * unmapped areas, and thus it should be converted to three regions of 10-25,
64  * 200-220, and 300-330.
65  */
damon_test_three_regions_in_vmas(struct kunit * test)66 static void damon_test_three_regions_in_vmas(struct kunit *test)
67 {
68 	static struct mm_struct mm;
69 	struct damon_addr_range regions[3] = {0,};
70 	/* 10-20-25, 200-210-220, 300-305, 307-330 */
71 	struct vm_area_struct vmas[] = {
72 		(struct vm_area_struct) {.vm_start = 10, .vm_end = 20},
73 		(struct vm_area_struct) {.vm_start = 20, .vm_end = 25},
74 		(struct vm_area_struct) {.vm_start = 200, .vm_end = 210},
75 		(struct vm_area_struct) {.vm_start = 210, .vm_end = 220},
76 		(struct vm_area_struct) {.vm_start = 300, .vm_end = 305},
77 		(struct vm_area_struct) {.vm_start = 307, .vm_end = 330},
78 	};
79 
80 	mt_init_flags(&mm.mm_mt, MM_MT_FLAGS);
81 	if (__link_vmas(&mm.mm_mt, vmas, ARRAY_SIZE(vmas)))
82 		kunit_skip(test, "Failed to create VMA tree");
83 
84 	__damon_va_three_regions(&mm, regions);
85 
86 	KUNIT_EXPECT_EQ(test, 10ul, regions[0].start);
87 	KUNIT_EXPECT_EQ(test, 25ul, regions[0].end);
88 	KUNIT_EXPECT_EQ(test, 200ul, regions[1].start);
89 	KUNIT_EXPECT_EQ(test, 220ul, regions[1].end);
90 	KUNIT_EXPECT_EQ(test, 300ul, regions[2].start);
91 	KUNIT_EXPECT_EQ(test, 330ul, regions[2].end);
92 }
93 
__nth_region_of(struct damon_target * t,int idx)94 static struct damon_region *__nth_region_of(struct damon_target *t, int idx)
95 {
96 	struct damon_region *r;
97 	unsigned int i = 0;
98 
99 	damon_for_each_region(r, t) {
100 		if (i++ == idx)
101 			return r;
102 	}
103 
104 	return NULL;
105 }
106 
107 /*
108  * Test 'damon_set_regions()'
109  *
110  * test			kunit object
111  * regions		an array containing start/end addresses of current
112  *			monitoring target regions
113  * nr_regions		the number of the addresses in 'regions'
114  * three_regions	The three regions that need to be applied now
115  * expected		start/end addresses of monitoring target regions that
116  *			'three_regions' are applied
117  * nr_expected		the number of addresses in 'expected'
118  *
119  * The memory mapping of the target processes changes dynamically.  To follow
120  * the change, DAMON periodically reads the mappings, simplifies it to the
121  * three regions, and updates the monitoring target regions to fit in the three
122  * regions.  The update of current target regions is the role of
123  * 'damon_set_regions()'.
124  *
125  * This test passes the given target regions and the new three regions that
126  * need to be applied to the function and check whether it updates the regions
127  * as expected.
128  */
damon_do_test_apply_three_regions(struct kunit * test,unsigned long * regions,int nr_regions,struct damon_addr_range * three_regions,unsigned long * expected,int nr_expected)129 static void damon_do_test_apply_three_regions(struct kunit *test,
130 				unsigned long *regions, int nr_regions,
131 				struct damon_addr_range *three_regions,
132 				unsigned long *expected, int nr_expected)
133 {
134 	struct damon_target *t;
135 	struct damon_region *r;
136 	int i;
137 
138 	t = damon_new_target();
139 	for (i = 0; i < nr_regions / 2; i++) {
140 		r = damon_new_region(regions[i * 2], regions[i * 2 + 1]);
141 		damon_add_region(r, t);
142 	}
143 
144 	damon_set_regions(t, three_regions, 3);
145 
146 	for (i = 0; i < nr_expected / 2; i++) {
147 		r = __nth_region_of(t, i);
148 		KUNIT_EXPECT_EQ(test, r->ar.start, expected[i * 2]);
149 		KUNIT_EXPECT_EQ(test, r->ar.end, expected[i * 2 + 1]);
150 	}
151 
152 	damon_destroy_target(t);
153 }
154 
155 /*
156  * This function test most common case where the three big regions are only
157  * slightly changed.  Target regions should adjust their boundary (10-20-30,
158  * 50-55, 70-80, 90-100) to fit with the new big regions or remove target
159  * regions (57-79) that now out of the three regions.
160  */
damon_test_apply_three_regions1(struct kunit * test)161 static void damon_test_apply_three_regions1(struct kunit *test)
162 {
163 	/* 10-20-30, 50-55-57-59, 70-80-90-100 */
164 	unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
165 				70, 80, 80, 90, 90, 100};
166 	/* 5-27, 45-55, 73-104 */
167 	struct damon_addr_range new_three_regions[3] = {
168 		(struct damon_addr_range){.start = 5, .end = 27},
169 		(struct damon_addr_range){.start = 45, .end = 55},
170 		(struct damon_addr_range){.start = 73, .end = 104} };
171 	/* 5-20-27, 45-55, 73-80-90-104 */
172 	unsigned long expected[] = {5, 20, 20, 27, 45, 55,
173 				73, 80, 80, 90, 90, 104};
174 
175 	damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
176 			new_three_regions, expected, ARRAY_SIZE(expected));
177 }
178 
179 /*
180  * Test slightly bigger change.  Similar to above, but the second big region
181  * now require two target regions (50-55, 57-59) to be removed.
182  */
damon_test_apply_three_regions2(struct kunit * test)183 static void damon_test_apply_three_regions2(struct kunit *test)
184 {
185 	/* 10-20-30, 50-55-57-59, 70-80-90-100 */
186 	unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
187 				70, 80, 80, 90, 90, 100};
188 	/* 5-27, 56-57, 65-104 */
189 	struct damon_addr_range new_three_regions[3] = {
190 		(struct damon_addr_range){.start = 5, .end = 27},
191 		(struct damon_addr_range){.start = 56, .end = 57},
192 		(struct damon_addr_range){.start = 65, .end = 104} };
193 	/* 5-20-27, 56-57, 65-80-90-104 */
194 	unsigned long expected[] = {5, 20, 20, 27, 56, 57,
195 				65, 80, 80, 90, 90, 104};
196 
197 	damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
198 			new_three_regions, expected, ARRAY_SIZE(expected));
199 }
200 
201 /*
202  * Test a big change.  The second big region has totally freed and mapped to
203  * different area (50-59 -> 61-63).  The target regions which were in the old
204  * second big region (50-55-57-59) should be removed and new target region
205  * covering the second big region (61-63) should be created.
206  */
damon_test_apply_three_regions3(struct kunit * test)207 static void damon_test_apply_three_regions3(struct kunit *test)
208 {
209 	/* 10-20-30, 50-55-57-59, 70-80-90-100 */
210 	unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
211 				70, 80, 80, 90, 90, 100};
212 	/* 5-27, 61-63, 65-104 */
213 	struct damon_addr_range new_three_regions[3] = {
214 		(struct damon_addr_range){.start = 5, .end = 27},
215 		(struct damon_addr_range){.start = 61, .end = 63},
216 		(struct damon_addr_range){.start = 65, .end = 104} };
217 	/* 5-20-27, 61-63, 65-80-90-104 */
218 	unsigned long expected[] = {5, 20, 20, 27, 61, 63,
219 				65, 80, 80, 90, 90, 104};
220 
221 	damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
222 			new_three_regions, expected, ARRAY_SIZE(expected));
223 }
224 
225 /*
226  * Test another big change.  Both of the second and third big regions (50-59
227  * and 70-100) has totally freed and mapped to different area (30-32 and
228  * 65-68).  The target regions which were in the old second and third big
229  * regions should now be removed and new target regions covering the new second
230  * and third big regions should be created.
231  */
damon_test_apply_three_regions4(struct kunit * test)232 static void damon_test_apply_three_regions4(struct kunit *test)
233 {
234 	/* 10-20-30, 50-55-57-59, 70-80-90-100 */
235 	unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
236 				70, 80, 80, 90, 90, 100};
237 	/* 5-7, 30-32, 65-68 */
238 	struct damon_addr_range new_three_regions[3] = {
239 		(struct damon_addr_range){.start = 5, .end = 7},
240 		(struct damon_addr_range){.start = 30, .end = 32},
241 		(struct damon_addr_range){.start = 65, .end = 68} };
242 	/* expect 5-7, 30-32, 65-68 */
243 	unsigned long expected[] = {5, 7, 30, 32, 65, 68};
244 
245 	damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
246 			new_three_regions, expected, ARRAY_SIZE(expected));
247 }
248 
damon_test_split_evenly_fail(struct kunit * test,unsigned long start,unsigned long end,unsigned int nr_pieces)249 static void damon_test_split_evenly_fail(struct kunit *test,
250 		unsigned long start, unsigned long end, unsigned int nr_pieces)
251 {
252 	struct damon_target *t = damon_new_target();
253 	struct damon_region *r = damon_new_region(start, end);
254 
255 	damon_add_region(r, t);
256 	KUNIT_EXPECT_EQ(test,
257 			damon_va_evenly_split_region(t, r, nr_pieces), -EINVAL);
258 	KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1u);
259 
260 	damon_for_each_region(r, t) {
261 		KUNIT_EXPECT_EQ(test, r->ar.start, start);
262 		KUNIT_EXPECT_EQ(test, r->ar.end, end);
263 	}
264 
265 	damon_free_target(t);
266 }
267 
damon_test_split_evenly_succ(struct kunit * test,unsigned long start,unsigned long end,unsigned int nr_pieces)268 static void damon_test_split_evenly_succ(struct kunit *test,
269 	unsigned long start, unsigned long end, unsigned int nr_pieces)
270 {
271 	struct damon_target *t = damon_new_target();
272 	struct damon_region *r = damon_new_region(start, end);
273 	unsigned long expected_width = (end - start) / nr_pieces;
274 	unsigned long i = 0;
275 
276 	damon_add_region(r, t);
277 	KUNIT_EXPECT_EQ(test,
278 			damon_va_evenly_split_region(t, r, nr_pieces), 0);
279 	KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_pieces);
280 
281 	damon_for_each_region(r, t) {
282 		if (i == nr_pieces - 1) {
283 			KUNIT_EXPECT_EQ(test,
284 				r->ar.start, start + i * expected_width);
285 			KUNIT_EXPECT_EQ(test, r->ar.end, end);
286 			break;
287 		}
288 		KUNIT_EXPECT_EQ(test,
289 				r->ar.start, start + i++ * expected_width);
290 		KUNIT_EXPECT_EQ(test, r->ar.end, start + i * expected_width);
291 	}
292 	damon_free_target(t);
293 }
294 
damon_test_split_evenly(struct kunit * test)295 static void damon_test_split_evenly(struct kunit *test)
296 {
297 	KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(NULL, NULL, 5),
298 			-EINVAL);
299 
300 	damon_test_split_evenly_fail(test, 0, 100, 0);
301 	damon_test_split_evenly_succ(test, 0, 100, 10);
302 	damon_test_split_evenly_succ(test, 5, 59, 5);
303 	damon_test_split_evenly_fail(test, 5, 6, 2);
304 }
305 
306 static struct kunit_case damon_test_cases[] = {
307 	KUNIT_CASE(damon_test_three_regions_in_vmas),
308 	KUNIT_CASE(damon_test_apply_three_regions1),
309 	KUNIT_CASE(damon_test_apply_three_regions2),
310 	KUNIT_CASE(damon_test_apply_three_regions3),
311 	KUNIT_CASE(damon_test_apply_three_regions4),
312 	KUNIT_CASE(damon_test_split_evenly),
313 	{},
314 };
315 
316 static struct kunit_suite damon_test_suite = {
317 	.name = "damon-operations",
318 	.test_cases = damon_test_cases,
319 };
320 kunit_test_suite(damon_test_suite);
321 
322 #endif /* _DAMON_VADDR_TEST_H */
323 
324 #endif	/* CONFIG_DAMON_VADDR_KUNIT_TEST */
325